Furnace



May 21, 1935. w. GROTHE 2,002,030

FURNACE Original Filed July 9, 1928 2 Sheets-Sheet 1 I I g 'l 97 m3 90/ \ala loz /0/ m3 /0/ a fz 1 INVENTOR. I I [Va/fer firofhe /04 BY ms /07 z I I W. G ROTH E May 21, 1935.

FURNACE Original Filed July 9, 1928 2 Sheets-$heet 2 INVENT OR. Wa/fer 6/0 fhe B Y 217T ways 0 Patented May 21, 1935 I i Y 2,002,030

UNITED STATES PATENT OFFICE FURNACE Walter Grothe, Alameda, Calif., assignor to Caterpillar Tractor Co., San Leandro, Calif., a corporation of California Original application July 9, 1928, Serial No. 291,322. Divided and this application May 4, 1931, Serial No. 534,905

4 Claims. (Cl. 26310) The invention relates to furnaces, and particuis exactly flush with the floor of the opening 92,

larly to a door therefor. as indicated by the dotted lines 109 in Fig; 1.

. The object of the invention is to provide an Thus there is formed a. continuous and smooth improved door structure for a furnace. passageway for the materials being inserted into 5 This application is a division of application or withdrawn from the furnace. Further, by 5 Serial Number 291,322, filed July 9, 1928, which arranging the door 9| to move downwardly when issued as Patent No. 1,825,059, dated September being opened, it is possible to utilize full insula- 29, 1931. I tion above the door where large heat losses would Description of figures Otherwise I, therefore, claim as my invention; 10

1. A furnace comprising a shell having an opening therein and'insulation projecting outwardly above said opening, a door vertically slidable across said opening and adapted to close the opening when the door is in an upper position with the top thereof adjacent said insulation, and means for moving said door from said upper pogg fi g gi g gfi gsffi2 3 ,22 Operatmg sition to a lower'position, said top of the door being adapted to register with the bottom bound- Description of mechanism ing said opening when the door is in the lower 20 position.

2. A furnace comprising a shell having an opening therein and insulation projecting out- Wardly above'said opening, a door vertically slidable across said opening and adapted to close the opening when the door is in an upper position With the top thereof adjacent said insulation, means for moving said door from said upper position to a lower position, said top of the door being adapted to register with the bottom bounding said opening when the door is in the lower position, and a stop for maintaining said top and bottom in registry.

3. A furnace comprising a shell having an opening therein and insulation projecting outwardly above said opening, and a door movable fa i i 333 g giggg flig ifij gggj with respect to said opening and adapted to close the opening with the door top adjacent said in- 94, pass over pulleys I02 ournaled 1n the shell Sulation @g g' r g g'g gg gaz' 9 4. A metallurgical furnace comprising a shell 40 i i b Cr ed t 1? g; having an opening therein and insulation proransa ed 30m 9 jeoting outwardly adjacent a bounding surface and rotatable with ashaft I01 suitably o'urnaled of Said opening and a shdably mounted d the shell 5. The end of the shaft m1 carries on movable with respect to sald openmg and adapthandle convement'ly disposed t ed to close said opening with an edge of the door 45' by the operator. Preferably the relationship and beneath and adjacent Said insulation adjustment of the actuating linkages for the door 9| are such that the top of the door when lowered WALTER GROTHE.

10 Fig. 1 is a sectional view of a furnace in which ,the improved door is installed;

Fig. 2 is a front elevation of the furnace with the shell broken away to show the door structure, with the door in the closed position. Fig. 3 is similar to Fig. 2 with the door in the open position. 1

Access to the interior annular chamber 3| within which are placed the articles to be treated, is afforded through a sliding door. This door preferably comprises a block 9|, made up of suitable insulating material, adapted to slide" vertically in an opening 92 provided in the shell 6. The block 9! is vertically reciprocated by a pair of rods 93 at their lower ends joined by a cross member 94 and sheathed in guiding tubes 96. The vertical movement of the rods and of the door is adjustably limited by an auxiliary rod 91 carrying adjusting nuts 98 forming a stop. The rod passes through an aperture in a portion of aframe 99 secured to the shell.

In order to counterbalance the weight of the 

